Blunt injuries to branches of the aortic arch

Scapulothoracic dissociation: evaluation and management

Scapulothoracic dissociation is an infrequent injury with potentially devastating outcomes. Knowledge of this injury is based on small patient series and case reports. The aim of this article is to review the evaluation, management and functional outcomes following scapulothoracic dissociation. Often caused by high traction forces applied to the shoulder girdle, there is a complete loss of the scapulothoracic articulation with lateral scapular displacement and intact skin. This is frequently associated with muscular, ligamentous and osseous injuries to the shoulder girdle, vascular injuries to the subclavian, or axillary, vessels and brachial plexus lesions. In the acute setting, the timely diagnosis of the associated neurovascular injuries is crucial. Severe neurovascular and soft tissue compromise often requires an early above-elbow amputation. Further, complete brachial plexus avulsions are associated with a limited potential for functional recovery.

Review of branch aortic injuries in blunt chest trauma

OBJECTIVES

To review the incidence, mechanisms of injury, diagnosis and treatment of injuries to the major branches of the thoracic aorta within the thoracic cavity following blunt trauma.

METHODS

Medline, Embase and Cochrane were searched using appropriate key word and MeSH headings. Full text articles were retrieved where there was any information relating to the mechanism of injury, incidence of injury, diagnosis, treatment or outcome in patients with injuries to the brachiocephalic, subclavian or carotid arteries within the thoracic cavity following blunt chest trauma.

RESULTS

The reported incidence of these injuries varied widely, most injuries were related to rapid deceleration injuries or falls. Diagnosis depends on a high level of clinic suspicion and appropriate investigations include helical CT scanning and arteriography. Treatment options have expanded in recent years with the use of endovascular stents; however, the optimal treatment remains uncertain.

CONCLUSIONS

Aortic branch injuries must be actively excluded in patients with suspicious mechanisms of injury. Guidelines determining appropriate investigative pathways and methods of treatment should be developed at all trauma centres.

Ruptured chronic traumatic mycotic pseudoaneurysm of the ascending aorta

We report a rare case of posttraumatic chronic mycotic pseudoaneurysm of the ascending aorta presenting with acute rupture. The uniqueness of the case lies in its unusual etiology, presentation, and management with direct repair of the aorta without using cardiopulmonary bypass.

Quantification of traumatic hemomediastinum using transesophageal echocardiography: impact on patient management

STUDY OBJECTIVES

To determine whether the quantitative evaluation of hemomediastinum using transesophageal echocardiography (TEE) is predictive of the presence of a traumatic disruption of the thoracic aorta (TDA) or its branches in patients who have sustained severe blunt chest trauma.

DESIGN

Retrospective study.

SETTING

ICU of a tertiary referral teaching hospital.

PATIENTS

Forty-one patients sustaining severe blunt chest trauma (32 men, nine women; mean age, 43+/-16 years; mean Injury Severity Score, 39+/-22) who underwent a TEE study were divided into two groups, patients with (group TDA+, n=15) or without (group TDA-, n=26) major vascular injury diagnosed using an alternative method such as aortography, surgery, or necropsy. The control group included 41 age- and sex-matched patients with an unremarkable TEE study performed to rule out an intracardiac source of emboli.

INTERVENTIONS

The presence of hemomediastinum was quantitatively assessed by measuring the distances between the esophageal scope and anteromedial aortic wall (distance 1), and between the posterolateral aortic wall and left visceral pleura (distance 2) at the level of the aortic isthmus. An observer who was unaware of both medical history and final diagnosis measured the distances.

MEASUREMENTS AND RESULTS

In group TDA+, TEE demonstrated aortic injuries in 13 patients, revealed an isolated hemomediastinum in one patient (ruptured intercostal arteries), and was unremarkable in the remaining patient, who sustained a disrupted right subclavian artery. No associated major vessel injuries were diagnosed in the group TDA- (normal aortograms). When compared to the control group, mean distances were greater in patients with chest trauma (distance 1=5.5+/-4.4 mm vs 2.7+/-0.8 mm, p=0.001; distance 2=3.8+/-5.0 mm vs 1.2+/-0.3 mm, p=0.02). The corresponding distances were even greater in group TDA+ when compared with group TDA- (distance 1=8.6+/-5.9 mm vs 3.7+/-1.5 mm, and distance 2=7.1+/-7.0 mm vs 2.0+/-1.7; for both differences, p<0.01). A threshold value of 5.5 mm for distance 1 or 6.6 mm for distance 2 had a sensitivity of 80%, a specificity of 92%, a positive and negative predictive value of 86% and 89%, respectively, for the diagnosis of underlying major vascular injury.

CONCLUSIONS

TEE allows quantitative assessment of traumatic hemomediastinum. The presence of a large hemomediastinum requires further evaluation by aortography, even if the thoracic aorta appears normal during the TEE examination, in order to rule out an underlying major vascular injury which may be outside the field of view of the echocardiographer.

A soccer victim: late rupture of the ascending aorta after violent physical trauma

A 56-year-old man without previous medical history or risk factors for coronary artery disease, presented with chest pain 2 weeks after violent blunt chest trauma. He was as a spectator, beaten and kicked almost to death during an amateur soccer match. Because of embarrassment, this was denied till shortly after his death. Shortly before the patient died, thoracic CT-scan showed a dissecting aneurysm of the ascending aorta in association with pericardial and bilateral pleural effusion. He suddenly died in-hospital due to heart tamponade secondary to rupture of the aneurysm into the pericardial space. At autopsy, the intimal layer of the aorta showed no atherosclerotic changes. The intimal rupture was located just above the origin of the right coronary artery.

Angiography in blunt thoracic aortic injury

PURPOSE

Recent studies have suggested that transesophageal echocardiography (TEE) can be used as the primary imaging method in patients suspected of traumatic rupture of the thoracic aorta. A segment of the aorta and the aortic arch branches cannot be adequately evaluated in all patients by TEE. To assess the impact of these limitations of TEE, this retrospective study examined the aortographic features of traumatic aortic or great vessel injuries in a large number of patients.

MATERIALS AND METHODS

We retrospectively reviewed clinical and imaging features of 89 patients with a history of blunt chest trauma and angiographic evidence of traumatic injury to the thoracic aorta or to its branches.

RESULTS

Of these 89 patients, 72 had aortic rupture alone. One (1%) of these ruptures occurred at the distal ascending aorta, a potential blind spot for TEE. Seventeen patients (19%) had 24 injuries to the aortic arch branches: in 14 of these 17 patients, the aorta was intact, whereas three patients also had aortic rupture. Seventy percent of the injuries to the aortic arch branches were not suspected on physical examination.

CONCLUSION

Twenty percent of patients in our retrospective series had traumatic involvement of aortic arch branches or the distal ascending aorta. These vascular injuries may be suboptimally assessed or overlooked if TEE is used as the sole imaging modality in the evaluation of patients with blunt chest trauma.

Blunt-Trauma Carotid Artery Injury

In brief Injury to the carotid artery can occur in athletes by direct blow to the neck or by hyperextension of the neck. After such injury, symptoms may be mild or transient. Catastrophic complications such as stroke can occur if the injury is not recognized and treated. Neurologic changes such as transient weakness or transient unilateral blurred vision that occur after a hyperextension injury or a direct blow to the neck may indicate a carotid artery injury. A careful neurologic examination can help identify most carotid artery injuries, but because the symptoms of injury may not appear immediately, follow-up may be necessary. Treatment may consist of anticoagulation therapy or operative repair.

Posttraumatic innominate artery aneurysm with occlusion of the common carotid artery at its origin by an intimal flap

Blunt trauma involving the innominate and carotid arteries is a rare occurrence that can be lethal or have serious neurologic sequelae. To our knowledge this is the first reported case in the international literature describing the association of posttraumatic innominate artery aneurysm with total occlusion and thrombosis of the common carotid artery at its origin by an intimal flap. The diagnostic problems created by this unusual injury are discussed. In this case the patency of the distal portion of the common and internal carotid arteries was demonstrated by magnetic resonance angiography (MRA), whereas color duplex and digital arteriographic studies were unsuccessful. This demonstration was crucial to patient management. Since no studies are available comparing color duplex imaging, conventional arteriography, and MRA in the evaluation of blunt carotid trauma, this case study is presented to demonstrate the utility of MRA in emergency situations. In addition, we analyze the possible pathogenesis and discuss the surgical treatment.

Traumatic lacerations of the aorta and great vessels with a normal mediastinum at radiography

The possibility of a "normal" mediastinum at conventional chest radiography in a patient with a lacerated aorta or great vessel from blunt thoracic trauma has not been evaluated objectively. All 1991 members of the Society of Thoracic Radiology were sent a questionnaire asking for examples of such cases. A similar questionnaire was placed in the newsletter of the Society of Cardiovascular and Interventional Radiology. The literature also was reviewed for cases. Seventy-eight of 327 questionnaires were returned with responses. Eight responders reported 12 examples of a normal mediastinum radiograph in a patient with a lacerated aorta. Review of the same radiographs by the authors yielded three normal and nine subtly abnormal mediastina. One additional normal radiograph was obtained of a patient with a lacerated great vessel. Another 16 cases of lacerated aortae (n = 12) and great vessels (n = 4) in patients with normal mediastina were found through a literature search; images from three of these were reviewed by the authors. Although this is an infrequent event, the mediastinum can be normal at plain chest radiography with traumatic lacerations of the aorta and great vessels.

The normal mediastinum in blunt traumatic rupture of the thoracic aorta and brachiocephalic arteries

In a review of 52 articles, published between 1953 and 1989, 656 patients with blunt traumatic rupture of the thoracic aorta or brachiocephalic arteries were identified. Of these, 608 (92.7%) had an abnormal mediastinum on initial chest radiographs obtained in the emergency department, thus allowing early detection of the vascular injury. Unfortunately, 48 (7.3%) of these patients had a normal mediastinum on their initial chest radiographs. This appears to occur when the traumatic pseudoaneurysm is not accompanied by associated mediastinal hemorrhage or hematoma formation, and the pseudoaneurysm is either small or is situated in such a way that it does not alter the mediastinal contour. The use of accessory clinical and radiographic signs to indicate the need for aortography has been shown to be of very low yield, but would have allowed the early detection of an additional 5.6% of the reported cases. Performing aortography solely on the basis of a history of major decelerating blunt trauma to the thorax remains the only way, in the acute emergency department setting, to detect the 1.7% of patients with aortic or brachiocephalic arterial rupture who have no mediastinal abnormality or accessory clinical or radiographic signs of vascular injury. There is evidence from the literature, however, to suggest that the evaluation of serial chest radiographs obtained at close intervals for the first month following trauma for the development of mediastinal abnormality or large hemothorax is an acceptable alternative to the routine performance of aortography in those blunt chest trauma victims with no clinical or radiographic suspicion of vascular injury.

Blunt injuries to the aortic arch vessels

Thirty patients with 33 vascular injuries from blunt trauma to the brachiocephalic branches of the aortic arch are reported. To our knowledge, this is the largest series reported to date of blunt injuries to these vessels. Mechanisms of injury included deceleration, traction, and crush. Half of the injured vessels were the innominate artery, and a quarter each were the common carotid and subclavian arteries. Common associated injuries were head injuries, hemopneumothorax, lung contusion, long bone fractures, and brachioplexus injuries. Widened mediastinum and extrapleural hematoma were common radiographic findings, and aortic rupture was frequently suspected. Angiography was performed in all patients to identify precisely the nature and site of the injury. Surgical approaches varied with the anatomical site of the injury and required consideration of vascular control in chest, neck, and upper extremity. Twenty-seven patients are alive 6 months to 10 years after injury. Eighteen of 20 vascular reconstructions were patent at follow-up. No patient with brachioplexus injury had return of neurological function.

Serial aortography assesses stability of "atypical" aortic arch ruptures

The victim of a high speed motor vehicle accident sustained an ascending aortic laceration as well as avulsion of the left subclavian artery. Initial management of the tears was conservative. The case is typical of "atypical" aortic arch tears except that the patient survived without emergent surgery. Serial aortography proved useful in assessing stability of the tears, providing opportunity to observe the natural history of these injuries angiographically. The distribution of aortic arch injuries following blunt trauma is reviewed.

Management of injuries of the thoracic and abdominal aorta

Thirty-five patients had surgery for injuries of the aorta at the Los Angeles County-USC Medical Center over a 4 1/2 year period. There were 27 survivors. The principles of management were to operate without delay if there was evidence of continued bleeding after initial fluid replacement as occurred in 11 patients. For the 24 patients who became stable after initial resuscitation, a more deliberate plan of management was used. Blood pressure was carefully monitored and controlled to avoid hypertension. Priorities for associated injuries were established and in several cases, they took treatment precedence over the aortic injury. Delay was sometimes necessary to utilize the more experienced personnel. In no instance did a stabilized patient hemorrhage during the delay. The most common injury seen was a blunt disruption of the proximal descending aorta. The details of the operative technique for this injury have been reported herein, along with a justification for not using either pump bypass or shunt to perfuse the distal aorta during the period of aortic cross-clamping.

Radiographic manifestations of mediastinal hemorrhage from blunt chest trauma

The diagnosis of rupture of the thoracic aorta or its major branches depends largely on the recognition of mediastinal hemorrhage from the initial chest radiograph and subsequent thoracic aortography. This review discusses the radiographic manifestations of mediastinal hemorrhage, including widening of the mediastinum; a ratio of mediastinal width to chest width greater than 0.25; abnormalities of aortic contour; opacification of the aortopulmonary window; depression of the left main bronchus; deviation of the trachea to the right; deviation of the nasogastric tube to the right; the apical cap sign; widening of the paraspinal lines; widening of the right paratracheal stripe; and left hemothorax. The relationship of these manifestations to major thoracic arterial injury is examined. Pitfalls in the radiographic evaluation of mediastinal abnormalities are considered, and indications for computed tomography of the thorax and thoracic aortography in the severely injured patient are reviewed.

Combined median sternotomy and posterior lateral thoracotomy: a method for proximal and distal thoracic aortic exposure

A method for exposure of the heart, ascending aorta, aortic arch vessels, and descending thoracic aorta in a single surgical field is presented. Five illustrative cases are reviewed. Indications for use include trauma to the aorta and arch vessels, aneurysms or dissections, ductus aneurysms, or complex or secondary coarctations of the aorta.

Management of subclavian and innominate artery injuries

Subclavian and innominate arterial injuries are life-threatening and require aggressive treatment. Physical findings, chest x-ray examinations, and a high index of suspicion led to expoloration in seventeen of twenty-two patients in this series, but the selective use of arteriography is helpful. Primary repair was accomplished in nineteen of the twenty-two patients. Wide proximal exposure proved to be accompanied by little morbidity with the reward of increasing survival to 95.5 per cent.

Traumatic rupture of the thoracic aorta

Eleven patients with aortic rupture secondary to non-penetrating thoracic trauma, recent in four patients and of longer standing in seven, have been operated upon. Every patient with an acute injury had a widened mediastinum in the chest skiagram. The diagnosis of traumatic rupture was made by aortography in each case. The operative procedure involved cardiopulmonary bypass, left heart bypass or aorta to aorta bypass shunt. There was one postoperative death. It is recommended that in the acute stage a rupture of the aorta secondary to trauma should be repaired as soon as possible, while ruptures of long standing should be electively repaired.